It would be one thing for Kevin Nealon, minor celebrity, to go on TV as Kevin Nealon, minor celebrity, and say: ``Hey, some people know my name. I drink this beer. You oughta drink it too.`` Nobody doubts that ``Saturday Night`` cast members may well have a beer after finishing a show. It might even be a Lite.

But he did the ad as ``Kevin Nealon, Subliminal Advertising Expert,``

which is nothing more than a weasel`s way to bring to mind his Mr. Subliminal character, the guy who says something fatuous in a normal tone of voice and then says what he`s really thinking or what he wants the listener to do in quick asides muttered immediately afterward.

In a show that, from the start, has relied on finding successful, sloganeering characters and writing skits for them over and over until they become part of the national zeitgeist, this borders on heresy.

We have all experienced the kind of instant cultural impact ``Saturday Night`` characters can have, from Roseanne Roseannadanna to Billy Crystal`s Fernando to this year`s copy kid. One night, they`re on; the next Monday, you`re unable to fill your mug without some office comedic genius going, ``The Stevester. Gettin` some coff-fee. Steveman. Lookin` mahh-velous.``

I should clarify my disappointment. I don`t mean to imply that Mr. Subliminal selling out is nearly as traumatic as if one of the previously mentioned characters had done so. Mr. Subliminal did star in a couple of inspired bits playing off the dissembling at Persian Gulf war press conferences, but other than that his appearances have mostly demonstrated that Nealon can switch with facility between two tones of voices.

And he certainly was far from the first to use the concept. Woody Allen did almost the same thing, only funnier, in the ``Annie Hall`` scene where his character goes back to Annie`s apartment for the first time. In the stilted conversation that follows, the true meaning of what they are saying is represented on the screen with subtitles. When, for instance, he says,

``Photography`s interesting `cause ... it`s a new art form and a set of aesthetic criteria have not emerged yet,`` the subtitle says, ``I wonder what she looks like naked.``

But the slope between Mr. Subliminal selling out for beer and the Wayne`s World boys doing it for, say, rolling papers is a slippery one.

Picture the Church Lady using her ``isn`t that special`` catchphrase to announce sale prices at an electronics chain.

It would, I believe, inspire in you a sensation not unlike the one I get every time I hear ``Rhapsody in Blue`` and think, without thinking, ``Hey, the United song!``

This kind of association, of course, is exactly what the advertisers want. But I can guarantee that its ability to tarnish a piece of music forever does not impress upon me the flying skill and hospitality of a particular airline.

``Saturday Night`` has done well consistently-other than ride a character to its grave-is parody TV commercials, exposing, along the way, almost everything stupid about the way ads are constructed and intended to be received.

But the very sorriest thing about the Subliminal Man ad (don`t watch it)

is that, for all its attempts at humor (Reader`s Digest) and claiming a portion of the cultural landscape (Utah), it ends up being more like what is mocked in the show`s ads than the skits it is trying to evoke (drink Bud Light).